Injector for impact pulverizer or the like



Jan. 2s, 195s A. J. FISHER 2,821,346

INJECTOR FOR IMPACT PULVERIZER OR THE LIKE Filed April 23. 1953 lNvENToR ndrew J .Fis/zer United States Patent() .INJECTOR .FOR IMPACT PULVERIZER R THE LIKE Andrew LFisher, JohnstowmfPa., assignor to Majac, Inc., JSharpsbnrg, Pa., -a corporation of vPennsylvania Application April 23, 1953,Serial No. 350,717

4 Claims. (Cl. 241-39) This invention relates to a new injector Afor projecting solid particles. More particularly, this invention Apertains to one or more s-uch injectors within an impact pulverizer or the like to reduce, for example, such solid particles in size.

The use of prulverizers to reduce the size of Asolidparticles by attrition has become increasingly important. Thus, in the power-producingfield using coal for fuel, impact ,pulverizers of`various kinds are employed to reduce the coal particles vtoa nneness capable of being gas borne to the `place of '.use. .Motive `lluid for such pulverizers is usually compressed air or stream which may be introduced into the pulverizers, -with solid particlesof a material to be reduced, `through various kinds of jets. A number of problems have attended jet operations in such pulverizers. For example, many of thejets have been 'worn unduly and many, moreover, wear -eccentrically. The consequencehas been, in many cases, shortened 'periods of `operation andlrelatively high repair or replacement costs. Further, there has been a tendency for someA jets 'to consume excessive power in attempting .too abrupt acceleration of the `solid particles passing through the jets. 'Still further, many jets, particularly those using steam as a motivefluid, have had a tendency tobecome caked with solidparticles. In other cases, problems havearisenin connection with the lack of uni- :tormityof the pattern `of the solid particles being projected through" the jet and/ or at times a tendency for the particles to have'other than a relatively straight course in the jetwhile `being so projected. Thereby, the'incidence of undue turbulence and of less effective impact with solid particles projected" by another jet in the same pulverizer,

"tended to'increase wear andreduce the etliciency of the "heavierpar-ticles tendV to be directed toward the axis of AAthe pattern and I injector. fticles is directedfalong a course which will provide appropriate `alignment -with thecolliding courses-of-particles Further, the path ofthe parfrom other such'new injectors used therewith. More- Iover,1provision is made in my new construction for a `morelgraudal acceleration of the solid particles to the desired impact speedwith increased eiciency.- In addition, segregation of the respective solid particles is rela- `"tively'well-maintained against tendencies-of the larger particlesinithestream.goingthrough the injector `to staitically attract -smaller particles. Still further, provision l ismadewhichtinhibits any tendency of the solid particles `to caketiffsteamjfor example, is used as a motiveffuid.

7 `The new 4injectoris highly .liexible in its capacity to handle 2,821,346 Patented Jan. 25, 1 958 ICC 2 diierent rate quantities of solid material Iundergoing reduction and, withal, is capable of'being so sturdily and relatively simply lconstructed that with its longerlifgthe cost andl operation expense incurred in connection with the `new injectors are reduced relatively markedly.

Other objects and advantages of `this invention will be apparent Vfromthe-following description and from lthe drawings, lwhich are illustrative only,'in which:

iFigure l is a-view of a lower part of-an impactpulverizer 'having a pairA of one embodiment of my new injector therein in aligned directly opposed relation;

Figure 2 is a view in vertical section-through the axis ofthe embodirnentof a new injector shown on the lefthandside of Figure l;

*Figure 3 is an end view of the embodiment showniin Figure 2 `taken in the `direction of thelines III-. -III in Figure l; and

Figure-4 is a modiiied embodiment of my new injector employing -a jet nozzle.

Referring to "Figure ll of the drawings, an impact fpulver'izer l10 may in its-lower part incorporate a pair of my new injectors 1-1'in aligned opposed relation and `respectively within a housinglZ. The innerrends 13 vofhous ings 'IZ-mayopen into an impact chamber 14 which'may extend upwardly to a classication and recirculation part of pulverizer 10 which need not be illustrated .for :the purposes of this description. In such classiiication and -recirculation, -particles not reduced tosullcient ineness in the spacell-S, as a result of the attrition of the particles upon one another `caused by theircolliding when discharged from injectors 11, may be recirculated to injectorsllll through downcomer pipes 16. Inaddition, .the downcomer `pipes 16 may fbewutilized, `in `the apparatus shown, for acontinuous fresh-feed o f s olidparticles with any such recirculated solid particles as described. zParlticles ,rising upwardly :from lspace 15 y inimpact chamber '14 whichtare-'of suicient linenessare -carried awayby a motive vfluideither'to afurther classification station ior to a rplace of use or storage, as-may bedesired. `Impact chambermay `be closed by ayplate 14a at its lower end and be provided therein with a wear resistant member .14b.

An velbow pipe `17 may be used to connect downcomers 1'6 respectively with the-entranceortconduitends ,18 Aof Ynewinjectors 11. :In the apparatus illustrated, the feed to `injectors .11 in the form of fresh solid particles or in the formof'fresh solid particles and recirculated ,solid particles, may beso fedfby. gravity or in the presenceof a 4streamofair or steam moving down downcomers 16 with such particles. Under equilibrium operating conditions, it may rnormally `be expected that a portion of `the motive fluid initially entering the pulverizer A1.0 through pipes 46 and injectors 11 will be recirculated through the downcomers .16 with the solid particles passing therethrough,ftl1e balance of such motive fluid passing out of apparatus 10 with the sufficiently finely divided solid vparticles entrained therein.

provision. may be made for the longitudinaladjustment v.of injectors 11 in housings f12 to vary the distance between the vrespective discharge ends 19 to injectors 11 for-.optimumfoperation in accordance with factors such as, for example, `the quantity, the average size and the specicgravity of the solid particles, and, the pressure of `themotive iluid available, as will be understood by those skilled inthe impact pulverizer art. In the latter ycase of such longitudinal adjustment, the elbows 17 respec- 3 tively adjacent ends 18 may each be provided with an expansion and contraction sleeve to accommodate any such axial adjustment.

An embodiment of my new injector is shown in more detail in Figure 2 and may comprise a casing 20 at the inlet end 18, which casing may be provided with a flange 2 1V for connection to an adjacent flange on elbow 17. Within casing 20 a frustum member 22 is aflxed as by a press-fit engagement between surface 23 of casing 2t) and surfaces 24 and 25 of nienber22. Member 22 is hollow so as to provide a central axial passage 26 therethrough in the form of a conical conduit tapering rela= tively gradually from the interior of the adjacent end of pipe 17 toward an apex on axis 27 in the direction of discharge end 19 o f the injector. A discoidal flange 28 is an integral part, in the embodiment shown, of the inner end of member 22 and is provided with surface 25 therearound. A cylindrical flange 29 of vreduced diameter relative to the diameter of surface is also provided in the embodiment shown and made integral with flange 28 and member 22. An injector barrel 30 in the form of a right cylinder is provided with a bore 31 and a slightly larger counterbore 32, which counterbore fits over flange 29 to which it is held by set screws 33. A hollow boss 34 is welded to the exterior of barrel 30 around its cardinal compass points and provides a hole of sufficient depth through boss 34 and barrel 30 so that when drilled and tapped for set screws 33, such set screws will firmly secure barrel 30 to casing 20 and member 22. Whenever the set screws 33 `are loosened, the barrel 30 can be removed in case it may be desired to affix a barrel of different dimensions or to replace a liner 35. Liner 35 may be press-fitted into barrel 30 and made of a material which is highly resistant to any abrading by solid particles. Thus, liner 35 may be made out of tungsten carbide or other hard material in place of the relatively soft steel out of which the balance of the new injector may be constructed.

Between the flanges on which the cylindrical surfaces 24 and 25 are provided, the wall 36 is spaced radially inwardly from casing 20 and its surface 23 a suflicient distance to provide a manifold chamber 37 which is annular and supplied with a motive fluid through a pipe tap 38 welded around an opening 39 leading to the interior of chamber 37. An outlet from chamber 37 is provided in the form of inclined apertures 40 extending through flange 28 and circumferentially spaced and arranged around axis 27 and the discharge end of throat 26. Each aperture 40 has an axis along an element 41, in the embodiment shown, of a generally hollow cone having its apex at 42 on axis 27 within barrel 30 and adjacent the discharge end 19 thereof. Apertures 40 may have a straight portion 43 adjacent manifold chamber 37 and a flared portion 44 adjacent bore 45 within the interior of liner 35 and flange 29. The radially outermost longitudinal element of the flaring portions 44, which are conical in the embodiment shown, is generally parallel to axis 27.

In operation, motive fluid in the form, for example, of compressed air or steam under pressure, may be supplied through a pipe 46, tap 38 and opening 39 to chamber 37, whence the motive fluid will jet into bore 45 in the general conical arrangement of elements 41 yet with suffcient diffusion under the effect of the flaring portions 44 to entrain solid particles passing through passage 26 in the direction of the arrows therein and project such solid particles out through the discharge ends 19 of the respective injectors 11 into a collision with each other as shown by the impact arrows in the vicinity of the numeral 15 in the impact space in chamber 14 (Figure l). It appears that the new construction not only maintains a more uniform pattern, normal to axis 27, of the solid particles being thus projected but inhibits the abrasion of liner 35 by such particles and yields a longer operating life. Moreover. the reduction in area in passage 26 and the correspondence between the area of passage 26 and bore 45 is such with the introduction of motive fluid through the apertures 40, an eflcient and favorable acceleration characteristic is imparted to the solid particles relative to that of prior devices. Still further, the path of the solid particles in injectors 11 is held in a relatively straight course through the new injectors with possibly some tendency for heavier particles or a somewhat greater concentration of solid particles to work toward the center of the particle pattern in the stream passing along axis 27. The inlet end of passage 26 is unobstructed, in the embodiment shown, with a reduction in any tendency of the material to cake even when a motive fluid like steam may be used. The jetting of motive fluid through the circumferentially arranged and spaced apertures 40 appears to maintain a separation of particles so smaller particles in the entrained solid material seem to have less tendency to be attracted to or agglomerate with larger particles. Another new feature of my injector is its flexibility in that the variation in quantities of solid particles and size of particles that can be processed through my new injectors in practical operations appear to be more extensive than in prior devices.

In the modified embodiment of this invention shown in Figure 4, the parts thereof corresponding generally in construction and functioning are similarly numbered with the addition thereto of a prime factor. In the Figure 4 structure, the lower part of elbow 17 may be constructed, as shown, to include therein a throat passage 26 provided by the tapering of walls 36' in the direction of bore 45. A boss 47 on the outside of the bend ot elbow 17 may be drilled and tapped for the insertion of a jet nozzle 48 having an orifice 49 to project a motive fluid like steam or compressed air into the interior of elbow 17 generally toward the discharge end of passage 26. A pipe 50 may also be screwed into the drilled and tapped portion of boss 47 to conduct motive fluid to the entrance end of nozzle 48 in the manner that motive fluid is conducted through pipe 46. Between cylindrical surfaces 24' and 25 on elbow 17, an annular recess 37' may be provided to constitute a manifold to supply such motive fluid to the circumferentially arranged and spaced apertures 40. A cylindrical ring 51 may span the distance between the sides of recess 37 and make tight contact with the surfaces 24 and 25 by being welded thereto around the respective edges of ring 51 to complete a new injector of this invention as a part, in this embodiment, of elbow 17'. Ring 51 may be drilled and tapped at 52 to engage and hold the adjoining end of pipe 46. In the operation of a modified injector embodiment such as that shown in Figure 4, the stream of motive fluid issuing from orifice 49, as illustratively indicated in Figure 4, will at least tend to be deflected by the flow of solid particles and motive fluid descending through downcomcr 16 and the upper part of elbow 17. Hence, `at the discharge end of throat 26', the jet issuing from orifice 49 will approach parallellism with the axis 27' which is coincident with the axis of bore 45. In addition, jet 48 does not obstruct passage 26 or the interior of elbow 17' and, moreover, may serve to hinder any tendency of heavier solid particles to settle toward or on the lower interior surface of elbow 17' as it bends toward the horizontal axis 27 thereof. Still further, the presence of jet 48 may be used to insure desired acceleration of solid particles through the modified injector 11.

Various changes and modifications may be made in my new construction without departing from the spirit of this invention or the scope of the appended claims.

I claim:

1. In an attrition impact pulverizer injector for projecting solid material, in combination, a member having a passage with inwardly inclined sides, means for feeding solid particles to the larger end of said passage, a relatively short barrel in axial alignment with said passage and having a diameter larger than the smaller end of said passage, and a plurality of apertures positioned in spaced circumferential relation around said member and discharging into said barrel, means for supplying a motive tluid to the entry end of said apertures, the `axes of said circumferential apertures intersecting the axis of said barrel in a direction toward the discharge end thereof.

2, In an injector for an impact pulverizer, in combination, a conical conduit, means for supplying solid particles to the larger end of said conduit, a barrel connected to the other end of said `conduit in axial alignment therewith, a plurality of apertures positioned circumferentially and outwardly relative the opening of said conduit into said barrel, the axes of said circumferential apertures intersecting the axis of said barrel adjacent the end thereof away from said conduit, said apertures further having portions flaring towards said barrel, and means for supplying a motive fluid through said circumferentia1 jets.

3. In an injector for an impact pulverizer, in combination, a gradually tapering conduit having a larger inlet end and a smaller outlet end, means for circulating solid particles to said inlet end of said conduit, a cylindrical barrel having an internal diameter somewhat greater than said outlet end of said conduit, said cylindrical barrel further being in axial alignment with said conduit `and secured thereto at the outlet end thereof, a plurality of apertured jets positioned circumferentially around said conduit and discharging into said barrel, the axes of said jets lying in a cone having its apex on the axis of said barrel adjacent the end thereof away from said conduit, the outer ends of said jets further being ared toward said barrel and the elements in said flaring ends nearest to tangency with said barrel being generally parallel to the axis of said injector.

4. In an injector for an opposed jet impact pulverizer or the like, in combination, a member having a tapered passage, means for providing a stream of solid particles and motive fluid to one end of said passage, a relatively short barrel connected to the other end of said passage in axial alignment therewith and having a diameter larger than the diameter of said other end of said passage, a plurality of apertures positioned circumferentially around said passage and discharging into said barrel, the apex of the axes of said apertures being generally along the axis of said barrel adjacent but within the discharge end thereof, said apertures being in generally conical arrangement around said member opening into said barrel, and means for supplying a further stream of motive fluid to said apertures for discharge there through to accelerate said solid particles.

References Cited in the le of this patent UNITED STATES PATENTS 250,999 Taggart Dec. 13, 1881 424,638 Barclay et al. Apr. 1, 1890 992,144 Babcock May 16, 1911 1,833,341 Thompson Nov. 24, 1931 2,119,887 Myers June 7, 1938 2,310,265 Sweeney Feb. 9, 1943 2,376,616 Oechsler et al May 22, 1945 2,387,548 Wiegand Oct. 23, 1945 2,543,517 Anderson Feb. 27, 1951 

